Will Emirates launch the 777X?

PARIS — Emirates, the biggest operator of the Everett-built Boeing 777, is pressing for more information about a successor aircraft before considering an order for the replacement of the U.S. manufacturer’s bestselling airliner.

“We’re working closely to get to specifications we’re happy with,” Emirates President Tim Clark said in an interview today. “That means layouts, the seats, the galleys, getting the weights right, getting the fuel burn.”

Clark has said he may need as many as 275 777s for replacement and expansion, a requirement so large his airline is likely to become the so-called launch customer of the successor plane. While Emirates is more advanced in talks with the Boeing Co. than other carriers, it doesn’t expect to be ready to table an order at the Paris Air Show in June, Clark said.

Boeing’s 777 is the centerpiece of the plane maker’s wide-body strategy, a lucrative segment of the civil aviation market that’s coming under fresh attack from Airbus and its new A350, specifically the A350-1000 that’s similar in size.

The Airbus model will hold 350 passengers and is promising 25 percent greater operating efficiency than the best-selling 777 variant, the 777-300ER. The successor, dubbed 777X, will have new wings and engines. Boeing in March named a general manager for the project and said General Electric Co., the sole powerplant supplier for the 777-300ER, would be the engine partner.

Emirates has ordered a total of 139 777 planes, which seat about 365 people and cost $315 million at list price in the most popular variant. Customers typically receive discounts.

Other airlines that have expressed potential interest in the 777X include British Airways and Lufthansa.